Handlebars provides the power necessary to let users build semantic templates. In versions 4.0.0 through 4.7.8, the `@partial-block` special variable is stored in the template data context and is reachable and mutable from within a template…
Exact source revision recorded 30 Oct 2026 05:49:05 UTC. It does not establish the source's current position. Latest evidence.
euvd · EUVD-2026-16849
PublishedHandlebars provides the power necessary to let users build semantic templates. In versions 4.0.0 through 4.7.8, the `@partial-block` special variable is stored in the template data context and is reachable and mutable from within a template via helpers that accept arbitrary objects. When a helper overwrites `@partial-block` with a crafted Handlebars AST, a subsequent invocation of `{{> @partial-block}}` compiles and executes that AST, enabling arbitrary JavaScript execution on the server. Version 4.7.9 fixes the issue. Some workarounds are available. First, use the runtime-only build (`require('handlebars/runtime')`). The `compile()` method is absent, eliminating the vulnerable fallback path. Second, audit registered helpers for any that write arbitrary values to context objects. Helpers should treat context data as read-only. Third, avoid registering helpers from third-party packages (such as `handlebars-helpers`) in contexts where templates or context data can be influenced by untrusted input.
EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON.
Original publisher date fields
datePublished: Mar 27, 2026, 9:05:42 PM
dateUpdated: Sep 4, 2026, 12:04:55 PM
3 related source bulletins · separate from aliases
RHSA-2026:10175: Red Hat Security Advisory: Red Hat OpenShift Dev Spaces 3.27.1 Release.
CVE-2025-61728 · CVE-2025-62718 · CVE-2026-2332 · CVE-2026-4800 · CVE-2026-4926 · CVE-2026-22731 · CVE-2026-25679 · CVE-2026-26999 · CVE-2026-27137 · CVE-2026-27606 · CVE-2026-29054 · CVE-2026-32305 · CVE-2026-32695 · CVE-2026-33186 · CVE-2026-33433 · CVE-2026-33805 · CVE-2026-33870 · CVE-2026-33871 · CVE-2026-33937 · CVE-2026-33938 · CVE-2026-33939 · CVE-2026-33940 · CVE-2026-33941 · CVE-2026-34986 · CVE-2026-40175
msrc_CVE-2026-33938: Handlebars.js has JavaScript Injection via AST Type Confusion by tampering @partial-block
CVE-2026-33938
RHSA-2026:34342: Red Hat Security Advisory: Cluster Observability Operator 1.5.0
CVE-2020-7753 · CVE-2021-33623 · CVE-2024-4068 · CVE-2024-45338 · CVE-2024-52011 · CVE-2025-22868 · CVE-2025-22870 · CVE-2025-22872 · CVE-2025-47911 · CVE-2025-58190 · CVE-2026-1526 · CVE-2026-1528 · CVE-2026-2229 · CVE-2026-4800 · CVE-2026-4867 · CVE-2026-6321 · CVE-2026-6322 · CVE-2026-6734 · CVE-2026-9277 · CVE-2026-9697 · CVE-2026-12143 · CVE-2026-12151 · CVE-2026-25680 · CVE-2026-25681 · CVE-2026-29063 · CVE-2026-32141 · CVE-2026-33228 · CVE-2026-33671 · CVE-2026-33814 · CVE-2026-33891 · CVE-2026-33894 · CVE-2026-33895 · CVE-2026-33896 · CVE-2026-33937 · CVE-2026-33938 · CVE-2026-33939 · CVE-2026-33940 · CVE-2026-33941 · CVE-2026-39821 · CVE-2026-42506 · CVE-2026-48779
- Source published
- Mar 27, 2026, 9:05:42 PM (timezone not stated)
- Source modified
- Sep 4, 2026, 12:04:55 PM (timezone not stated)
- Observed here
- 30 Oct 2026 05:49:05 UTC
- Source terms
- ENISA EUVD · source terms and attribution apply
Original source record · Cite this exact observation · Complete original publisher JSON
This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: euvd · ENISA EUVD · source terms and attribution apply. Source text is retained; field grouping and change labels are provided by ChangeIntel.
EUVD CVSS 3.1 · 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H